TXT · Text & Data tools

ISSN Validator

Batch by newline

Values to check

Result

ISSNscheme0values0valid0invalid0unreadable

Weights 8 to 2 mod 11. The check character can be X.

Open the full check digit validator with Luhn, IBAN, ISBN, GTIN, VIN, ISIN, Verhoeff, and Damm

Shareable link

Settings are written to the URL as you change them. Nothing differs from the defaults yet.

Mod 11 over 7 digits

An ISSN is 8 characters. The first 7 identify the serial, and the eighth is a mod 11 check character weighted 8, 7, 6, 5, 4, 3, 2.

As with ISBN-10, a remainder of 10 needs a character rather than a digit, so X appears in the final position. 0378-5955 is the canonical example from the ISSN standard.

Print and online versions

A journal published in print and online carries two different ISSNs, and both are real. Confirm which one a citation style or repository expects, because the check digit cannot distinguish them.

Frequently Asked Questions

How is an ISSN validated?

The first 7 digits are weighted 8 down to 2 and summed. The check character is 11 minus that sum modulo 11, written as X when the result is 10 and 0 when the remainder is zero.

Does the hyphen matter?

No. An ISSN is normally printed as 4 digits, a hyphen, then 4 characters, but the hyphen is stripped before the check runs.

What is an ISSN-L?

The linking ISSN groups the print and online versions of the same serial under one number. It is formatted and validated exactly like any other ISSN.

Pages locked to one scheme

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